content: /* Copyright (C) 2016-2018 Alibaba Group Holding Limited
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  
  // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf;
  
  import static com.google.protobuf.IsValidUtf8TestUtil.DIRECT_NIO_FACTORY;
  import static com.google.protobuf.IsValidUtf8TestUtil.EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT;
  import static com.google.protobuf.IsValidUtf8TestUtil.EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT;
  import static com.google.protobuf.IsValidUtf8TestUtil.HEAP_NIO_FACTORY;
  import static com.google.protobuf.IsValidUtf8TestUtil.LITERAL_FACTORY;
  import static com.google.protobuf.IsValidUtf8TestUtil.testBytes;
  
  import com.google.protobuf.IsValidUtf8TestUtil.ByteStringFactory;
  import com.google.protobuf.IsValidUtf8TestUtil.Shard;
  
  import junit.framework.TestCase;
  
  /**
   * Tests cases for {@link ByteString#isValidUtf8()}. This includes three
   * brute force tests that actually test every permutation of one byte, two byte,
   * and three byte sequences to ensure that the method produces the right result
   * for every possible byte encoding where "right" means it's consistent with
   * java's UTF-8 string encoding/decoding such that the method returns true for
   * any sequence that will round trip when converted to a String and then back to
   * bytes and will return false for any sequence that will not round trip.
   * See also {@link IsValidUtf8FourByteTest}. It also includes some
   * other more targeted tests.
   *
   * @author jonp@google.com (Jon Perlow)
   * @author martinrb@google.com (Martin Buchholz)
   */
  public class IsValidUtf8Test extends TestCase {
    /**
     * Tests that round tripping of all two byte permutations work.
     */
    public void testIsValidUtf8_1Byte() {
      testBytes(LITERAL_FACTORY, 1, EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
      testBytes(HEAP_NIO_FACTORY, 1, EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
      testBytes(DIRECT_NIO_FACTORY, 1, EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
    }
  
    /**
     * Tests that round tripping of all two byte permutations work.
     */
    public void testIsValidUtf8_2Bytes() {
      testBytes(LITERAL_FACTORY, 2, IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
      testBytes(HEAP_NIO_FACTORY, 2, IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
      testBytes(DIRECT_NIO_FACTORY, 2, IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
    }
  
    /**
     * Tests that round tripping of all three byte permutations work.
     */
    public void testIsValidUtf8_3Bytes() {
      // Travis' OOM killer doesn't like this test
      if (System.getenv("TRAVIS") == null) {
        testBytes(LITERAL_FACTORY, 3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
        testBytes(HEAP_NIO_FACTORY, 3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
        testBytes(DIRECT_NIO_FACTORY, 3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
      }
    }
  
    /**
     * Tests that round tripping of a sample of four byte permutations work.
     * All permutations are prohibitively expensive to test for automated runs;
     * {@link IsValidUtf8FourByteTest} is used for full coverage. This method
     * tests specific four-byte cases.
     */
    public void testIsValidUtf8_4BytesSamples() {
      // Valid 4 byte.
      assertValidUtf8(0xF0, 0xA4, 0xAD, 0xA2);
  
      // Bad trailing bytes
      assertInvalidUtf8(0xF0, 0xA4, 0xAD, 0x7F);
      assertInvalidUtf8(0xF0, 0xA4, 0xAD, 0xC0);
  
      // Special cases for byte2
      assertInvalidUtf8(0xF0, 0x8F, 0xAD, 0xA2);
      assertInvalidUtf8(0xF4, 0x90, 0xAD, 0xA2);
    }
  
    /**
     * Tests some hard-coded test cases.
     */
    public void testSomeSequences() {
      // Empty
      assertTrue(asBytes("").isValidUtf8());
  
      // One-byte characters, including control characters
      assertTrue(asBytes("\u0000abc\u007f").isValidUtf8());
  
      // Two-byte characters
      assertTrue(asBytes("\u00a2\u00a2").isValidUtf8());
  
      // Three-byte characters
      assertTrue(asBytes("\u020ac\u020ac").isValidUtf8());
  
      // Four-byte characters
      assertTrue(asBytes("\u024B62\u024B62").isValidUtf8());
  
      // Mixed string
      assertTrue(asBytes("a\u020ac\u00a2b\\u024B62u020acc\u00a2de\u024B62").isValidUtf8());
  
      // Not a valid string
      assertInvalidUtf8(-1, 0, -1, 0);
    }
  
    private byte[] toByteArray(int... bytes) {
      byte[] realBytes = new byte[bytes.length];
      for (int i = 0; i < bytes.length; i++) {
        realBytes[i] = (byte) bytes[i];
      }
      return realBytes;
    }
  
    private void assertValidUtf8(ByteStringFactory factory, int[] bytes, boolean not) {
      byte[] realBytes = toByteArray(bytes);
      assertTrue(not ^ Utf8.isValidUtf8(realBytes));
      assertTrue(not ^ Utf8.isValidUtf8(realBytes, 0, bytes.length));
      ByteString leaf = factory.newByteString(realBytes);
      ByteString sub = leaf.substring(0, bytes.length);
      assertTrue(not ^ leaf.isValidUtf8());
      assertTrue(not ^ sub.isValidUtf8());
      ByteString[] ropes = {
          RopeByteString.newInstanceForTest(ByteString.EMPTY, leaf),
          RopeByteString.newInstanceForTest(ByteString.EMPTY, sub),
          RopeByteString.newInstanceForTest(leaf, ByteString.EMPTY),
          RopeByteString.newInstanceForTest(sub, ByteString.EMPTY),
          RopeByteString.newInstanceForTest(sub, leaf)};
      for (ByteString rope : ropes) {
        assertTrue(not ^ rope.isValidUtf8());
      }
    }
  
    private void assertValidUtf8(int... bytes) {
      assertValidUtf8(LITERAL_FACTORY, bytes, false);
      assertValidUtf8(HEAP_NIO_FACTORY, bytes, false);
      assertValidUtf8(DIRECT_NIO_FACTORY, bytes, false);
    }
  
    private void assertInvalidUtf8(int... bytes) {
      assertValidUtf8(LITERAL_FACTORY, bytes, true);
      assertValidUtf8(HEAP_NIO_FACTORY, bytes, true);
      assertValidUtf8(DIRECT_NIO_FACTORY, bytes, true);
    }
  
    private static ByteString asBytes(String s) {
      return ByteString.copyFromUtf8(s);
    }
  
    public void testShardsHaveExpectedRoundTrippables() {
      // A sanity check.
      int actual = 0;
      for (Shard shard : IsValidUtf8TestUtil.FOUR_BYTE_SHARDS) {
        actual += shard.expected;
      }
      assertEquals(IsValidUtf8TestUtil.EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT, actual);
    }
  }
  